The present invention relates to inhibition of oxidation of a cooked, dehydrated meat product.
In the past, development work for manufacturing dehydrated meat products, particularly for use as garnishes, has been directed to and emphasized the use of reconstituted meat for reasons of quality and consistency. However, owing to food legislation and food regulations in Europe, particularly in Germany, reconstituted meat is not accepted as meat in all cases and thus can create label declaration problems. In addition, owing to consumer preference, there is a growing demand for dehydrated genuine meat pieces, i.e., meat pieces which have not been subjected to disintegration and subsequent reconstitution and reshaping which, therefore, retain the original meat form and structure, but dehydrated genuine meat is very susceptible to lipid oxidation and is difficult to protect with antioxidants and thus has a shorter shelf-life than reconstituted meat. For example, freeze-dried genuine meat tends to become rancid rapidly because of its porous form and texture.
In order to overcome lipid oxidation, various antioxidants have been utilized and proposed. Among such antioxidants are various synthetic antioxidants. However, owing to toxicological and nutritional considerations, only a very few synthetic antioxidants are permitted in food applications, e.g., butylhydroxytoluene (BHT), butylhydroxyanisole (BHA), propyl gallate (PG) and t-butyl hydroquinone (TBHQ), but even these antioxidants now are being examined by regulatory agencies and consumer activists. Thus, that has urged the need to explore for and employ new sources of antioxidant substances, which include various substances including tea, rosemary extract, tocopherol and ascorbyl palmitate, for example.
Ascorbic acid, which long has been utilized for curing meat and for color stabilization of meat, as illustrated, for example, by U.S. Pat. Nos. 2,772,169, 2,955,042, 3,690,901 and 4,016,292 and by Great Britain Patent Specification 1 363 209, also has been utilized as an antioxidant for preserving meat, as illustrated for example, by U.S. Pat. Nos. 2,772,169 and 4,741,915. In my work, however, it was found that ascorbic acid presents certain disadvantages when combined with dehydrated meat, in that, because a reaction takes place between lysine, an essential amino acid found in the meat protein, and oxidized ascorbic acid (dehydroascorbic acid), which results in deamination of the lysine, that reaction causes not only the formation of a red pigment, i.e., 2, 2"-nitrilodi-2 (2")-deoxyascorbic acid (NDA), which is desirable in red meat, but also loss of and reduction of the amount of lysine, which is undesirable, and that reaction also tends to produce off-flavors.
Maillard reaction products also have been proposed as being potentially useful as antioxidants, as shown by Lingnert, et al., "ANTIOXIDATIVE MAILLARD REACTION PRODUCTS I. PRODUCTS FROM SUGARS AND FREE AMINO ACIDS", J. Food Processing and Preservation, 4, 161 (1980). As disclosed by Lingnert, Maillard reaction products which are said to be most effective as antioxidants are derived from reactants which include "basic" amino acids, with histidine and arginine being shown to be most effective, and those amino acids and lysine being described as having "considerable antioxidative effect" in a model system of emulgated linoleic acid. Additionally, the Lingnert data lead to the conclusion that cysteine, a reactant utilized commonly to prepare maillard reaction meat flavor products, would not provide satisfactory antioxidant activity.